Comparison Xiaomi Redmi Watch 3 Active vs Xiaomi Redmi Watch 3

The main way to connect a wearable gadget with external devices. For smartwatches and fitness bands (see "Type"), this refers to a connection to a smartphone or tablet, while in the case of watch-phones, it usually refers to headsets.

— Bluetooth. Wireless technology for direct communication of various devices with each other. This is the most popular interface in smartwatches and bracelets: Bluetooth modules can be made very tiny, the communication range even in the earliest versions reaches 10 m, and different generations of Bluetooth are mutually compatible in terms of basic functionality. Specifically, the versions nowadays are as follows:

• v2.0. The earliest standard used in modern wearable gadgets. The possibilities of such a connection are more modest than those of more advanced versions, but they are often quite enough.
• v3.0. A standard that combines classic Bluetooth v 2.0 and a high-speed “add-on” for transferring large amounts of data.
• v4.0. Further, after 3.0, improvement of Bluetooth: in addition to the classic and high-speed format, this version added Bluetooth Low Energy technology. Support of this technology is especially useful in fitness trackers, which usually transmit small amounts of data, but constantly.
• v4.1. Modification of the 4.0 standard described above with improved protection against interference while working with LTE mobile communications. ...i> v4.2. Another improvement of the 4.0 standard, which introduced, in particular, improved data protection and increased connection speed.
• — v 5. The fifth generation of Bluetooth was released in 2016. The key innovation in version 5.0 was the expansion of capabilities related to the Internet of Things. Thus, in the Bluetooth Low Energy protocol, it became possible to double the data transfer rate (up to 2 Mbit/s) at the cost of reducing the range, and also quadruple the range at the cost of reducing the speed; In addition, a number of improvements have been introduced regarding simultaneous work with a large number of connected devices.
• — v 5.1. Update of the version described above v 5.0. In addition to general improvements in the quality and reliability of communication, this update introduced such an interesting feature as determining the direction from which the Bluetooth signal is coming. This makes it possible to determine the location of connected devices with centimeter accuracy.
• —v 5.2. The next, after 5.1, is the fifth generation Bluetooth update. The main innovations in this version are a number of security improvements, additional optimization of power consumption in LE mode and a new audio signal format for synchronizing parallel playback on multiple devices.
• —v 5.3. The Bluetooth v 5.3 wireless communication protocol was introduced at the dawn of 2022. Among the innovations in it, they accelerated the process of negotiating a communication channel between the controller and the device, implemented the function of quickly switching between the operating state in a low duty cycle and a high-speed mode, and improved the throughput and stability of the connection by reducing susceptibility to interference. When unexpected interference occurs in Low Energy mode, the procedure for selecting a communication channel to switch from now on has been accelerated. There are no fundamental innovations in protocol 5.3, but a number of qualitative improvements are evident in it.
  
  Of course, to use all the capabilities of a particular version of Bluetooth, it must be supported not only by the gadget itself, but also by the smartphone/tablet to which it is connected.

Types of notifications, as well as basic voice communication features supported by the gadget.

- Notifications. In classic smart watches and fitness trackers, the specific functionality of such notifications can be different – from a regular sound or vibration signal to the ability to display on the screen and even respond. But in any case, such notifications are often more noticeable to the user than the own signal from a smartphone located deep in a pocket or bag.

— Voice control. The ability to control the device through voice commands. In order for a smartwatch or fitness tracker to perform some simple feature, it is enough to say its name aloud.

— Voice assistant. In watches with voice assistant support, the level of user interaction with the device is displayed in a new qualitative way. The most popular virtual assistants are Google Assistant and Amazon Alexa. In Apple devices, the role of an assistant is performed by Apple Siri, in Samsung wearable gadgets — a virtual assistant Bixby. Unlike the voice control function, the assistant does not just turn on this or that feature, but allows you to perform certain operations in applications that require feedback.

— Sound signal. The ability to give sound signals using the built-in speaker. This feature will be useful primarily in situations where the gadget is not on hand — for example, if it is used as an ala...rm clock and is removed at night.

— Vibration. Vibration signal similar to that used in mobile phones. In wearable gadgets, such a signal is especially convenient due to the fact that the device is constantly in contact with the wearer's skin, so that the vibration is perfectly felt — and regardless of the level of noise around. In addition, vibration mode is also useful in quiet environments where a loud sound signal is undesirable.

— Built-in microphone. Own microphone built into the body of the device. Such equipment can be used for different purposes, depending on the type and features of the gadget. First of all, voice communication is impossible without a microphone. Another feature for which a microphone is required is the voice assistant (see above). And in children's smartwatches, it may be possible to remotely turn on the microphone from the parent gadget and listen to what is happening around the child; see the relevant paragraph below for details.

— Speakerphone(speaker). The ability to work the gadget in hands-free mode, using the built-in speaker and microphone for conversation. In a conventional smartwatch (see "Type"), this feature allows you to talk through the watch without removing the smartphone from your pocket; in watch-phones, speakerphone allows you to do so without headphones and headsets, and for children's smartwatches, this feature is almost mandatory. However the volume of the built-in speaker is usually low, so in a noisy environment its power may not be enough.

The number of types of sports training supported by the smartwatch. The more of them, the wider the coverage of the potential audience is provided by a wearable gadget on the wrist.

The most common sports modes include running, walking, cycling, swimming, elliptical exercise, and so on. The quantity and quality of data for different sports depends on the technical level of equipment of a particular device. While some models only record heart rate and roughly calculate the number of calories burned, other smartwatches evaluate the effectiveness of a workout using a detailed list of data and even draw a conditional run track based on information from GPS satellites.

This block contains both various navigation systems ( GPS, Galileo) and auxiliary features for them ( aGPS, GPS tracking, maps, compass, altimeter , barometer). More about them:

— GPS module. GPS satellite navigation module built right into the watch/tracker. The initial purpose of such a module is to determine the current geographic coordinates; but how this information will be used depends on the specific type and model of the gadget. For example, in some devices GPS is used only for measuring the distance traveled and/or speed of movement, while more advanced models support full navigation and are equipped with built-in maps. In addition, this feature is almost mandatory in children's beacons (see "Type") — it is GPS that is responsible for determining the location of the child.

— aGPS. An auxiliary feature that allows you to speed up the start of the main GPS receiver. To work for its main purpose, such a receiver must update data on the location of navigation satellites; Obtaining this data in the classical way, directly from the satellites themselves, can take quite a long time (up to several minutes). This is especially true for the so-called "cold start" — when the receiver starts up after a long break in opera...tion, and the data stored in it has become completely outdated. aGPS (Assisted GPS) allows you to receive up-to-date service information from a mobile operator — from the nearest base station (this feature is supported by most operators nowadays). This can greatly speed up the startup process.

— GLONASS. This system is a Russian alternative to the American GPS. However it provides somewhat less accuracy, so GLONASS support is usually provided in addition to the GPS module. Simultaneous use of two systems, in turn, improves positioning accuracy.

— Galileo. European satellite navigation system, created as an alternative to the American GPS. Note that it is under the control of civilian departments, not the military. With a full fleet of 24 active satellites, the system gives an accuracy of up to 1 m in public mode and up to 20 cm with the GHA service. Working in conjunction with GPS, the Galileo system provides a more accurate position measurement, especially in densely populated areas.

— Maps. The feature of displaying topographic maps of the area with heights, relief and types of vegetation on the clock screen. Preinstalled maps are used for visual GPS navigation without being tied to a smartphone. Often, the ability to display maps is implemented in tactical smartwatches with a focus on tourism.

— GPS tracking. Many watches with the possibility of laying routes have the feature of guiding by the GPS track. At the same time, the wearable gadget acts as a navigator around the area, showing the route on the screen and suggesting where it is necessary to turn in one direction or another. Some smartwatches with a pronounced touristic bias also have a “Return Route” programme that allows you to go back along an already traveled route. In GPS tracker mode, trackpoints are usually recorded automatically based on the selected fixing interval. You can also mark a track point manually at any time.

— Compass. A classic compass is a device that indicates the direction to the cardinal points. Wearable gadgets usually use an electronic compass — a miniature magnetic sensor, the data from which, if necessary, are displayed on the display.

— Altimeter. A feature that allows you to determine the current altitude of the user's location. Note that the principle and format of the altimeter may be different. So, some models use barometer data for height measurements, others use information from a GPS sensor; the height itself can be determined relative to sea level, relative to some reference point, or in any of these ways, at the choice of the user. These details should be clarified separately.

— Barometer. A feature that allows you to determine the current atmospheric pressure. One of the applications of the barometer is weather forecasting: for example, a sharp drop in pressure usually signals the approach of bad weather. In addition, information from this sensor can be used to operate the altimeter (see above); and even if the gadget does not have an altimeter, the height difference between two points on the ground can be easily calculated from the pressure difference between them.

— TFT. The simplest type of liquid crystal panel used in colour displays. They provide a relatively low, but generally sufficient image quality, while they are much cheaper than more advanced options. This type does not require backlight — more precisely, the backlight is part of the screen itself and turns on with it. Of the unequivocal disadvantages, it is worth noting that many TFT panels have rather limited viewing angles; however, as technology improves, this drawback is gradually eliminated.

— IPS. A variety of LCD panels created in an attempt to eliminate the shortcomings of TFT. There are many subspecies of IPS panels, but they all feature high colour reproduction quality, excellent brightness and wide viewing angles. The disadvantage of this option is the relatively high cost.

— OLED. In this case, we mean the technology used to create the simplest monochrome displays. In such screens, each segment that makes up the image is a separate LED, which eliminates the need for external illumination (and even the display itself can be used as a flashlight).

— AMOLED. Screens based on a panel of active organic light emitting diodes. Similar to various types of TFT, this technology allows the creation of high-resolution colour displays. Its key feature is that the screen doe...s not require a separate backlight system — in AMOLED panels, each pixel glows independently, resulting in somewhat lower power consumption. At the same time, such screens are distinguished by good colour reproduction quality, excellent brightness and wide viewing angles, however, they are much more expensive than TFT.

— Super AMOLED. An enhanced version of the AMOLED technology described above, delivering more expansive colour reproduction and brightness, as well as improved touch accuracy and speed, all at a thinner display and lower power consumption. In addition, the degree of reflection of external light is reduced, such a panel gives less glare and is better visible in sunlight.

— E-Ink (E-Paper). Displays made using "electronic paper" technology; in addition, this category also includes screens such as Memory LCD. The classic E-Ink screen is black and white, does not have a backlight (however, it can be built into particular gadgets), has a very low refresh rate and is poorly suited even for stopwatches, not to mention videos or animated pictures. On the other hand, "electronic paper" is perfectly visible in bright light and has a very low power consumption: it requires electricity only when the image is changed, while a still image remains visible even when the power is completely turned off. Memory LCD screens, in turn, with the same advantages, are almost as good as classic LCD panels in terms of refresh rate, but for a number of reasons they are not widely used.

— Transflective. A specific type of LCD panels that can work both due to its own backlight and due to reflected light. In bright external light (for example, in the sun), such a screen effectively reflects it and does not require a separate backlight — however, it is still included in the design and turns on in low light. This type of operation can significantly reduce power consumption compared to traditional LCD screens, where the image is not visible without backlight; in addition, good visibility in bright light is also an important advantage. The main disadvantage of panels of this type is their high cost; in addition, they are made mostly monochrome.

- LTPO. OLED and AMOLED matrices with an adaptive refresh rate that varies over a wide range based on the tasks performed. When rendering dynamic frames, screens with LTPO technology automatically raise the refresh rate to the maximum values, while viewing static images, they automatically reduce it to the minimum. At the heart of the technology is a traditional LTPS substrate with a thin TFT oxide film on top of the TFT base. Dynamic control of the refresh rate is provided by controlling the electron flow. The key benefit of LTPO screens is their reduced power consumption.

The size of the display installed in the gadget; for round screens, respectively, the diameter is indicated.

A larger screen, on the one hand, is more convenient to use, on the other hand, it significantly affects the dimensions of the entire device, which is especially critical for wearable gadgets. Therefore, manufacturers choose the display size in accordance with the purpose and functionality of each specific model — so that there is enough space on the screen and the device itself is not too bulky.

It is also worth mentioning that screens with a similar size may have different aspect ratios. For example, traditional smartwatches are usually equipped with square or round panels, while in fitness trackers, screens are often made elongated in height.

Screen size in dots (pixels) horizontally and vertically. In general, this is one of the indicators that determine the image quality: the higher the resolution, the clearer and smoother the picture on the screen (with the same size), the less noticeable are the individual dots. On the other hand, an increase in the number of pixels affects the cost of displays, their power consumption and requirements for a hardware platform (more powerful hardware is required, which itself will cost more). In addition, the specifics of using smartwatches is such that there is simply no need to install high-resolution screens in them. Therefore, modern wrist accessories use displays with a relatively low resolution: for example, 320x320 with a size of about 1.6" is considered quite sufficient even for premium watches.

The density of dots on the screen of the gadget, namely, the number of pixels that are on each inch of the panel vertically or horizontally.

The higher the PPI, the higher the detail of the screen, the clearer and smoother the image is. On the other hand, this indicator affects the price accordingly. Therefore, the higher the density of points, the more advanced, usually, this gadget is in terms of general capabilities. However, when choosing a screen, manufacturers take into account the general purpose and functionality of the device; so that even a small number of PPIs usually does not interfere with comfortable use.

The maximum brightness in nits that the screen of the device produces.

The high-brightness displays remain legible under intense ambient light, which is important for quickly retrieving information from the dial outdoors on a clear sunny day. However, a large margin for this parameter affects the cost and power consumption of the display, which reduces the battery life of a wearable device.